make/lib/premake.mk

   1 #PREMAKE_SOURCE_COMPILER#########################################################
   2 # Compile any source-to-source languages before executing the majority of make ##
   3 #################################################################################
   4 define PREMAKE_SOURCE_COMPILER =
   5 # Find the sources for each source-to-source language
   6 $(foreach slang,$(SLANGS),
   7 $(eval SLANG_SRC := $(shell find $(SRC_DIR) -name "*.$(slang)" -not -name ".*"))
   8 # Foreach target type in the source-to-source language, add this source's
   9 # targets to the list of the current source-to-source language targets
  10 $(eval undefine SLANG_TRG)
  11 $(foreach trg,$($(slang)_TRG),
  12 $(eval SLANG_TRG += $(SLANG_SRC:%.$(slang)=%.$(if $($(slang)_STEM),$($(slang)_STEM).)$(trg))))
  13 # Stat the source file's last-modified time to the var SRC_TIME
  14 $(foreach src,$(SLANG_SRC),
  15 # Establish a command to run for compiling this file
  16 $(eval SHELL_CMD := cd $(dir $(src)) && $($(slang)_C) $($(slang)_FLAGS) $(notdir $(src)))
  17 # Evaluate missing targets
  18 $(eval FOUND_TRG := $(shell find $(dir $(src)) -name "$(basename $(notdir $(src))).*" -not -name ".*"))
  19 $(eval MISSING_TRG := $(filter-out $(FOUND_TRG), $(SLANG_TRG)))
  20 # Check timings of existing files
  21 $(eval SRC_TIME := $(shell stat -c %Y $(src)))
  22 # For each of the targets created by this source language, evaluate the
  23 # last-modified times of each potential target.  If the file does not exist, set
  24 # the time to '0', otherwise set it to the -c %Y result from statting the file.
  25 $(foreach srctrg,$(filter $(basename $(src))%, $(SLANG_TRG)),
  26 $(eval TRG_TIMES += $(if $(wildcard $(srctrg)),$(shell stat -c %Y $(srctrg)),0)==$(srctrg)))
  27 # Sort TRG_TIMES, which will produce a list of oldest-first files and timestamps
  28 # of the form [last-modified-deltatime]==[filename]
  29 $(eval TRG_TIMES := $(shell echo $(sort $(TRG_TIMES)) | $(call AWK_REVERSE_SQUASH)))
  30 # Evaluate the newest time from our ordered list by splitting the word up by its
  31 # '==' connectors and looking at the first word
  32 $(eval NEWEST_TRG_TIME := $(word 1,$(subst ==, ,$(TRG_TIMES))))
  33 # Find the older of the two times (between SRC_TIME and NEWEST_TRG_TIME)
  34 $(eval OLDER_TIME := $(firstword $(sort $(NEWEST_TRG_TIME) $(SRC_TIME))))
  35 # If the older of the two times is the newest target time found, then we need to
  36 # rebuild, but only if our build rule intends to actually make something.  If it
  37 # instead does not intend to actually make a target, drop a functional rule that
  38 # could hypothetically make the target for debugging and analysis purposes
  39 $(if $(MAKECMDGOALS),
  40 $(eval BUILDGOALS := $(filter-out clean scrub purge uninstall,$(MAKECMDGOALS))),
  41 $(eval BUILDGOALS := all))
  42 $(if $(and $(BUILDGOALS),$(or $(MISSING_TRG), $(filter $(OLDER_TIME),$(NEWEST_TRG_TIME)))),
  43 $(if $(findstring n,$(MAKEFLAGS)),
  44 $(SLANG_TRG):
  45         $(SHELL_CMD)
  46 ,
  47 $(info $(SHELL_CMD) $(eval $(shell $(SHELL_CMD)))))
  48 ))
  49 # Put these targets on the MAKE_TARGETS list to be removed during "clean",
  50 # regardless of whether or not they were built just now.
  51 $(eval MAKE_TARGETS += $(SLANG_TRG))
  52 )
  53 #/PREMAKE_SOURCE_COMPILER########################################################
  54 endef
  55